Flame safety and open lamp



T. M..CHANCE. FLAME SAFETY AND OPEN LAMP.

APPLICATION FILED APR. 26. IQII.

1,.i:23,618.1 Patented Den. 2,1919.

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LM; CHANCE. FLAME SAFETY AND,0PEN LAMP.

APPLICATION FILED APR. 26| 1917;

` Patented, Dec. 2,1919.

3 SHEETS-SHEET 2.

ravi FIL-LH I W/TNESSESI v Y l (i T. M. CHANCE.

FLAME SAFETY AND0PEN LAMP.

APPucAnoN man Amma. um.

1923,61 j Patented Dec.2,1919.

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AWT@ W W/ TNESSES: n /N VEN TOR burner.

UNEP AlY srarns THOMAS 1VI. CHANCE, 0F PHILADELPHIA, PENNSYLVANIA.

FLAME SAFETY AND LAMP.

Specification of Letters Patent.

Patented Dee. 2, 191e.

Application led April 26, 1917. Serial No. 164,675.

To all whom t may concern." Y

Be it known that I, THOMAS M. CHANGE,

a citizen of the United States, residing at Philadelphia, in the countyof Philadelphia and State of Pennsylvania, have invented a certain newand useful Improvement in Flame Safety and Open Lamps, of which thefollowing is a specification. The object of my invention is to providean improved type of flame safety lamp that will project a portion of thelight emitted by the flame into the space above, and in some casesbelow, said lamp. A further object of my invention is to provide a meansfor increasing the efficiency of the burner, in'thosetypes of lampsemploying a reigniting type of burner in connection with a gaseous fuel.Another object of my invention is to provide an improved acetylenegenerator whereby a safety lamp may Vbe constructed that will eliminatethe objectionable features hitherto encountered in lamps of this type.

To attain these ends I constructthe lamp to operate in the manner shownby the accompanying drawings, and described Ain detail in the followingspecification.A It will be understood, however, that I do not limitmyself to the particular constructions shown herein, but that thesetypes may be Widely varied without departing from the spirit of myinvention, and that the drawings shown herein are diagrammaticrepresentations of the general association ofrelements necessary totheoperation of my invention.

The drawing, Figure I, is a diagrammatic vertical cross-section of anacetylene safety lamp adapted to carry lout my invention. Fig. II is asimilar cross-section of a lamp employing a dierent arrangement ofreflectors and generator and a dierent type of Fig. III is Van enlargedvertical crossesection showing another type of reigniting burner.FigjI-V is a partial vertical cross-section illustrating-an improvedtype of combustion chamber. Like numbers in the several drawingsindicate like parts.

In the drawing Pig.V I, 1 indicates a Water chamber provided Vwithfilling opening 2,

in this case iitted with a ball valve, and pressure escape pipe 3. Thecalcium carbid container 4 is fitted with water feed tube 5, and

is provided with a water sealed cover 6, said cover 6 screwing intowater chamber 1 and supporting container 4 by screw thread 7.

Said water chamber 1 carries valve and water-feed valve stem 8 in ascrew thread in the base of said chamber. Said stem 8 is provided with aconical valve face at its `upper end, adapted to close communication Vbetween container 4 and the burner,-in this case a single jet steatiteburner 9 provided with self-contained reigniting prongs 10 and shield11,mounted on cover 6. Said stem 8 is enlarged near the operating screwthread at its lower end, said enlargement nearly filling` feed tube 5and providing a restricted water feed to the carbid contained in 4. Thisenlargement may be provided witha conical valve Vseat at its lower endto prevent leakage of water past the operating screw thread on said stemwhen said stem is screwed to its lowermost position. The stem S `is alsoprovided with an operating head at *its lower extremity. A filter 12 isheld in place in the top of cover 6 by filter support 13, said support13 housing over a tube 14 surrounding` valve stem 8. Said tube 14 slipsinto feed tube 5 when container 4 is being filled with carbid(preventing the falling of carbid into said tube 5), but is lifted Voutof tube 5 by the enlargement on valve stem 8 when container 4 and cover6 are screwed into place in water chamber 1.

The combustion chamber, or lamp top, is composed of bonnet 15, providedwith standards 16 connecting said bonnet with screw ring 17. Said screwring may be provided with a locking device 18, for locking said lamp topto the gas generator, the locking device being in thisv case shown as ofthe lead rivet, slip ring type. Said screw ring 17 is provided withreflecting element 19, the function of which is further described inthis specification.V Glass-ring 2O screws into screw ring 17 andsupports a horizontal gauze 21 carrying outer glass 22 and glass chimney23, which in turn support horizontal gauze 24 fitted with metal chimney25, outer gauze 26 and inner gauze 27 The admission of air forcombustion is secured through slots 28 in the wall of bonnet 15`and,gaskets 29 are placed between glass 22 and ganzes 21 and 24 to insure agas-tight fit.

y from the flame.

1, feed tube 5 slipping down over valve stem 8 and tube 14 being raisedby the enlargement on said stem. TWater is now introduced throughllingopening 2 and, the valve on' stem 8 being open, generation of.acetylene commences, the resulting gas passing thrbugh filter 12, andissuing at the orifice of burner The lamp may now be lighted and thelamp top, assembled as shown in Fig. I, is screwed in place on 'waterchamber 1. A lead rivet is inserted in locking device 18 and the rivetupset, thus isolating the entire internal mechanism Vof the lamp fromthe exterior.

As the lamp gradually heats up the air for combustion is heated bypassing downward through the annular space between the interior glasschimney 23 and exterior glass 22, both of these glasses becoming verywarm due to heat radiated and conducted Shield 11 likewise becomesheated and, acting as a reflective element, prevents excessivedissipation of heat from the reigniting prongs 10 on burner 9.

If the lamp be now subjected to the concussion due to shot-ring or otherrise in atmospheric pressure, the jet of gas issuing from the orifice ofburner 9 will be temporarily arrested, but immediately said jet isreestablished, after the passing cf the concussive wave, the flame isalso restablished by some portion of the mixture of acetylene `and airreaching the reigniting prongs 10 duringsaid restablishm'ent of the jet.

i The function of the double glass type of combustion chamber istwofold. in the rst place it assists materially in steadying the lampflame from the eifect of exterior air currents, etc., tends to increasethe etliciency of combustion by pre-heating the air supply and preventsthe chimney effect commonly encountered with under-feed lamps, such asthe Wolf lamp, when the lamp is introduced into atmospheres containingconsiderable percentages of liredamp or combustible gas. In the secondplace it greatly increases the safety of the lamp inasmuch as a lamp soconstructed comprises virtually two lamps in one. That is, if theexterior glass be broken, or even completely removed, the lamp flame isstill isolated by horizontal gauze 21, inner chimney 23, upperhorizontalgauze 24 and exterior and interior gauzes 26 and 27 respectively. Thusit will be readily seen that this type of lamp is more safe for use inlocations where the outer glass may become accidentally fractured, as

such fracture of the glass in the ordi-i nary type of lamp may result inimmediate passage of the flame to the exterior should the exterioratmosphere be inflammable. A further advantage ofthis conf struction isthat the inner glass is virtually spring-supported, horizontal ganzes 2land 211 acting as resilient cushions, and l have' in inflammableatmospheres, as there are four ganzes which must be passed on the inletside of the lamp before the lamp can fire the exterior atmosphere, andinlamps fitted with a chimney, such in lamps of the Muessler type,exterior ignitions are nearly always produced by passage of the flame onthe inlet side of the lamp, since the products of combustion in thechimney generally prevent ignitions down chimney. While in theconstruction herein shown there are but two ganzes isolating thedischarge of the lamp from the exterior, it will thus be seen that thecushion of dea-d gases in chimney will assist in preventing ignition onthe discharge side.` The chimney alsd assists in the vdraft of the lamp.

The reflecting element 19 serves to project a portion of the rays oflight emitted from the flame in a roughly conical path upward, (theapproximate path of one such ray being shown by the dot and dash lineA-L) andthereby provides an illuminated area immediately above the lamp,thus enabling the miner using` the lamp to make a careful inspection ofthe condition, of the roof or other space above him. Such inspection has hitherto been practically impossible of ac-Y complishment and it is awell known fact that in many districts more accidents have resulted fromfailure to properly inspect` the roof after safety lamps wereintroduced, than were formerly caused by ignitions of gas, due to theuse of open lamps. The only wayin which the roof can be inspected `withsafety lamps as at present constructed is by tilting the lamp, andvwhile such tilting could be practised to a moderate degree in lampsburning acetylene or other gas under pressure, it is fatal totheoperation of the common t e of oil burnin()` safet lam s as it resultsin immediate smoking of the glass. It should be noted that the lightprojected by the refiecting element need not necessarily remove anyconsiderable amount of light from the fluxemitted'by the flame i.

in a horizontal directioinfor said element can readilyvbe designed tomake use of light that would largely be lost by-abs'orptionin said CIK

be used in the upper portion of said bonnet, as shown in Fig; Il, shouldit be desired to illuminate the floor below'the lamp.

The method of operation of the generator shown in Fig. I is similar tothat commonly Vknown as the contact method, that is, the

water is introduced near the bottom of the carbid, the supply of waterdepending on the relation between the gas and water pressure; and theresultant excessive heating encountered in drip generators is lessened.Should the slacked carbid form a' crust about the orifice of the waterfeed, this may beeifectively broken up and normal conditionsrestablished by rotating the valve stem 8 by means of the milled head onthe lower end. This rotation will raise the valve stem up and down infeed tube 5 and perform the function commonly known as raking in thesmall generators now used for mine lighting. It will be noted that thevalve Y stem has some play before encountering the conical seat in cover6 so that a number of turns can be given in this raking process beforeshutting the gas supply olf.

The function of water-sealed cover 6 is the saine as that commonlyperformed by the Vcover of the belltype of generator, that is,

a water seal is provided to prevent the escape of gas, but with thisimportant addition, that mechanica-l means are provided for preventingfree flow Yof water between the water chamber and the interior of carbid`container 1, should the generator' be overturned. ln the drawing Fig.l, such flow is prevented by means of screw thread 7, said screwthread', while not necessarily forming a gas-tight fit, providing agreatly restricted frictional resistance so that free escape of the gasis prevented and the 'flooding ofthe generator with water, should thelamp be turned on its side, eliminated. This trouble due to flooding ofthe lamp just referred to would be inherent in rall types of watersealedgenerator in common use and would effectually prevent the use of suchgenerators in lamps of this kind. l have found, however, that by theaddition of a mechanical resistance to the hydraulic seal, a generatorthe generator is available that possesses the paramount advantage ofgas-tightness-a 'condition thatcould never be absolutely insured inlamps employing a gasket alone for the sealing of lcoupled with absoluteportability, that is, the generator can be overturned, swung from thehand or in other ways mistreated without seriously 'affecting Vitsoperation.` ltinight be `noted herethat the impossibility of insuringgas-'tightness in lampsusing gaskets for the sealing of the generator,has so militated against the use of this type of lamp that the acetylenesafety lamp as heretofore constructed has not been lpermitted in any ofthe principal mining districts ofthe world.`

Inv the drawing Fig. 11 the generator is similar in construction to thatshown in Fig. I, and need not be further described except to callattention to the fact `that the mechanical resistance, shown in Fic'. las screw thread 7 is here shown as a gasket 7 placed between the carbidcontainer Ll and cover 6, this gasket being placed in compression whencover G is screwed down on the carbid container 4, and also that movabletube lil is replaced by a stationary perforated tube 14. 1t will ofcourse be understood that this gasket could be placed at the lowerportion of carbid container il, and thus immersed in water, instead ofin the position shown.

The burner 9A in this drawing Fig. Il is shown as a two-jet burnerfitted with a wire reignitiiig coil 10 partially surrounded by shieldl1. The reigniter in this case is heated by the heat radiated from bothflames and performs the same function as reigniting'prongs 10 of theburner shown in Fig. i.

The combustion chamber or lamp top is in this case shown as of the YVolf type and is provided with annular top and bottom reflecting elements19 and 19a. The function of reflecting element 19 has been fully described in the description of the drawing Fig. 1. That of 19a issimilar, with the difference that the light rays reflected by 19 aredirected upward toward the roof while those reected by 19'd are directedtoward the space below the lamp, the approximate path of one such raybeing shown by the dot and dash line BB.

lt should be noted, however, that the rejecting element 191 is notdesigned to perirni the saine functions as that of the reflectorscommonly used in the .so-called porch type of safety lamp and that itssize should never be so great as to materially cut off the upward raysreflected by element- 19. In other words, the function of element 19u isin all cases subordinate to that of element 19, as inspection of theroof is generally of far greater importance than that of the floor. Thelight rays indicated bythe dot and dash lines A- anclB-B in the severaldrawings are roughlyl approximate as no allowance has been made forrefraction due to the exterior shield for preventing loss of heat fromYthe reigniting elen'lent. ln this case the burner 9, shown as of thesingle liet type` isprovided with helical coil l0 of nichel CIK maximumquantity of the heat received by` it from the lamp flame and reignitingelement, to said lamp flame and reigniting element, and at the same timeto lose by radiation and conduction a minimum quantity of heat. It willof course be understood that the function of the reigniting element issimilar to that described in the drawings Figs. I and II.

I have found that by the use of a heat .insulating device such as theshield 1l in the drawing Fig. III, a reigniting burner can besuccessfully operated with a reigniting element that would operatepoorly, if at all, when not provided with such a shield. As any lightlosses of the flame, due to the use of a reigniting element, are largelya function of the mass required by said element and of the proximity ofsaid element to the flame, it will be clear that a device such as theshield ll which permits the use of reigniters of less mass, and placedfarther from the flame, than would otherwise be possible, is exceedinglyadvantageous in increasing the efficiency of the lamp as a whole. Theshield also performs another important function in that it preventsaccidental breakage or deformation of the reigniting element when thelamp is 'being han dled during cleaning, etc.

The drawing Fig. IV illustrates a lamp of similar construction to thatshown in Fig. I with the exception that the lamp top,

or combustion chamber, is of different construction. Said drawing neednot be further described, therefore, except 'in so far as may berequired for understanding the operation of this type of combustionchamber.

In this drawing Fig. IV the glass ring support 20 supports a plate 21carrying tube 21a, said plate 21 supports outer glass 22, glass chimney23 and upper plate 2l carrying tube 24 sliding over tube 21a. Plate 24carries chimney 25, outer gauze 26 and inner gauze 27 in the same mannerthat gauze 24 supports these elements in the drawing Fig. I.

The function of the plates 21 and 24.` and tubes 21a and 24a issimilarto that performed by ganzes 21 and 24 of the drawing Fig. I. Theair for admission passes downward through these plates and tubes and isisolated from. the exterior atmosphere, and also from the annular spacebetween the glass 22 and chimney 23. I-Ience the lamp flame is doublyisolated from the exterior atmosphere, as in the drawing Fig. I, andbreakage of the exterior glass alone will not cause passage of llame tothe exterior. The incoming air will be pre-heated by passing downwardthrough tubes 21nu and 24" and these tubes will ofcourse be of vsuchcross-sectional area (or a plurality of such tubes will be used) as toinsure sulficient air supply for the proper combustion of the flame. Theadvantage of this method of construction is that it renders impossiblean ascending current of air and a descending current of air in the tubesat the same time, whereas this phenomena might possibly occur in theannular space between the glasses in the double glass type of lamp, suchas shown in Fig. I. rIhe Vresult achieved is parallel. to that reachedin the Gray type of lamp employing exterior tubes for air admission.

To insure the same degree of gauze protection as that shown in F ig. I,it will be understood that one or more ganzes may be placed within thesetubes, and also that the tubes should be such a sliding fit over oneanother as to eliminate the possibility of firing the exterioratmosphere by a leak between the walls of the tubes. The tube 24Ea mayadvantageously support va reflecting element 24J for projecting thelightrays horizontally, as this tube will of course cut off a certain amountof light and this disadvantage may be thus counteracted. It shouldbenoted thatV this reflecting element would be acting in` an absolutelydead atmosphere between theouter and inner chimneys and could thereforebe kept clean for comparatively long periods of time.

The use of double glass lchimneys with double gauze protection in oilburning safety lamps is known, and has previously been practised inlamps of the Muessler type, but without successful cormnercialV result,as the sooting of the interior glass by the oil-fed flame wasfoundcertain to occur whenever the lamps were built with glasses ItV ofa size that was practically feasible. will of course be seen that with afuel such as acetylene this trouble will not be encountered, and I havefound it possible to` operate lamps of this type for periods conlsiderably in excess of 100 hours without cleaning the ganzes orglasses7as under all proper operating conditions soot is not deposited by thecombustion of the flame.

It will of course be understood that the reflecting elements of thetypel herein described may readily be Vused with lampsV burning liquidfuels, and `of the types in common use, and the scope of this Vinventionis not limited to lamps of the gaseous fuel type. It should be pointedeut, however, that the low unit illumination of liq'- uid fuel safetylamps does not vproduce a roof or floor illumination comparableV to thatpossible with the acetylene type df lamp. Y

It will be understood that any type Vof more constant head of wateryduring opera` tion than would be the case were a chamber of uniformcross-section employed, and while in no way essential-to the operationof my invention, I have found it to be an advantageous type ofconstruction.

The functions of the regniting burner 9 are fully described in the U. S.`Patent 1,198,006 to Thomas M. Chance, and Aneed not be furtherdescribed here.

It will be understood that the type of generator and shielded reignitingburner herein described may be used with lamps that do not requireforaminous or other means for preventing exterior ignitions, suoli as inordinary open lights, `and that the use of the type of generator andshielded burner in open lamps is entirely within the scope of myinvention.

It will be understood that should excessive' generation of acetyleneoccur, the excess gas will blow back through the water in chamber 1 andescape to the exterior atmosphere by means of escape pipe 3. Should thelamp be extinguished by closing the gas valve carried on stem 8, thepressure in the generator, after building up to, or above, the operatinghead, will be relieved in the above manner, hence as soon asafter-generation ceases further generation of fresh gas will stop untilthe gas valve is again opened, permitting the pressure in said generatorto fall and fresh water to enter.

The type of mechanical resistance to be used in a water-sealed generatorof the kind described herein may be greatly varied, the use of a gasketor screw thread being typical examples of a large class of structuresthat may be used for reaching the same end. It should be pointed out,however, that Whether a separate member, such as a gasket or screwthread, be used, or whether the cover and carbid container be forcedtogether by a Vclose t, as for example, in a manner simr lar to the lidof a tin canister, the mechanical resistance so produced must besuiiicientto prevent the flooding of the generator when the lamp isoverturned, and also to prevent the water feed working with a highercapillary resistance than the mechanical resistance employed in thewater seal. I have found that under certain conditions a continuousover-generation of gas appears to'be produced if the water feedbeassisted by a high capillary resistance and the water seal is notprovided with suhcient mechanical resistance. It will be understood4that by the term mechanical resistance .where used 1n the speciicationand claims hereof, is meant any organism acting in conjunction with awater-seal which will so restrict or prevent the free flow of water fromthe water chamber to the interior of the generator as to attain the endsjust described.

The term foraminous in the claims and specificationhereof is intended toinclude materials with perforations, apertures or channels through whichair may freely pass, but which are too small to permit the propagationof combustion, Vand I have used the word foraminous to designatematerials containing such holes, aperturesor channels. The term glass inthe claims land specification hereof is intended to mean any transparentrefractory material.

It will also be understood that my invention is not confined to theoperation of portable lamp structures, but may be equally well employedwith stationary lamps.

Having described my invention I claim:

1. An improved safety lamp comprising in combination a source ofcombustible gaseous fuel, a reigniting burner adapted to utilize saidfuel, a reflecting shield for the insulation of the reigniting elementof said burner, and means for preventing the propagation of said flameto the exterior atmosphere.

2. An improved flame lamp comprisingin `combination an acetylenegenerator, a reigsigned my name at Philadelphia, Pennsylvania, this 25day of April 1917.

THOMAS M. CHANCE.

Witnesses:

H. M. CHANCE, CARL K. SCHULZE.

